Substantially all present-day copiers, printers, plotters, etc. include a controlling microprocessor which requires input calibration data for internal components so as to enable high quality production of documents. Since most such apparatus is produced so as to allow user-replacement of consumable items, entry of usage and calibration data must be performed by the user (or repair-person) who is performing the replacement operation. Any error in entry of calibration data can substantially degrade the apparatus or render the apparatus inoperative.
To determine usage of consumables, the prior art has generally been restricted to simple record-keeping entries which enable the user to know when replacement is required. For instance, copiers often display a count of the number of output pages and maintain an internal record of the number of rotations of the drum (or of an organic photoconductor web) to enable the processor to signal when service or replacement is required.
Replaceable developer modules are currently employed in many electrophotographic printers and copiers. Each developer module includes a supply of toner and toner carrier along with a mechanism to bring the toner/carrier mixture to a drum (or web) surface. To provide proper control signal levels for a laser exposure system, the control microprocessor adjusts the ratio of toner to carrier so as to achieve a proper mixture. One method for controlling the toner-to-carrier ratio is to provide an oscillator circuit whose frequency is varied by the toner-to-carrier ratio. Upon an initial installation of a new developer module, the control processor takes a number of minutes to accumulate sufficient data from the oscillator circuit to determine the toner-to-carrier ratio so as to enable a setting of the proper signal levels in the laser exposure system. If the developer module is removed from the apparatus or is transferred to another apparatus, the entire calibration procedure must be repeated.
While, as above indicated, printers and copiers have heretofore retained an output page count, such a raw page count does not take into account different wear levels created by different media types. For instance, a fuser assembly (which includes a pair of platen rollers, one or both being heated) manifests a surface breakdown phenomenon after approximately 80,000 pages of a standard media type. Different media types cause a variation in fuser assembly wear and a simple page count does account for such variations.
Fuser assemblies used with color printers employ a silicone oil to increase color saturation level and to provide a glossy finish to printed media sheets. Different media types require variations in the amount of applied oil. A control system is provided to enable the fuser assembly to know the particular type of media sheet so as to enable a determination of the amount of oil to be deposited. While the processor maintains track of cumulative oil usage, if the fuser assembly is removed or the stored data regarding oil usage is lost, there is no way to reconstruct the usage state of the fuser assembly when it is put back into service.
In a similar fashion, an electrophotographic drum includes a photosensitive layer that manifests a determined charge sensitivity. Such charge sensitivity data is employed as a control parameter in the power control loop of the laser exposure system. Heretofore, such charge sensitivity data has been entered by the operator. If, however, the drum is transferred between printers, as may happen during servicing, such data does not travel with the drum but must be reentered.
U.S. Pat. No. 5,049,898 to Arthur et al., assigned to the same assignee as this application, discloses a disposable printing assembly wherein an integral memory element stores data that characterizes the assembly. Arthur et al. provide an ink jet print head assembly with a memory which designates the color of ink in the print head, its amount, and the position of the ink jet orifice plate on the print head body. This data is read from the print head by a read/write element in the printer and is then used or displayed, as desired.
Many consumable, replacement parts for printers/copiers include a fuse that is integral to the replacement part and identifies whether the replacement part is new or used. If, upon insertion of the replacement part, the controlling microprocessor determines that the fuse is intact, the machine determines that the replacement part is new and zeros out its count values which indicate the remaining usable life for the part. When further input data concerning the replacement part is required, the microprocessor either indicates the need for such data to the user via a control panel or automatically gathers the data from a replacement part sensor (as in the case of the toner-to-carrier ratio in a developer module). Thereafter, the fuse is blown.
Such a prior art circuit is shown in FIG. 1 for an electrophotographic printer wherein each of a plurality of consumable parts are plug connected to a printer at an interface 10. The plug-connected consumable items include an oil pad module 12, a black (K) toner developer module 14, a color developer module 16, a fuser assembly 18, a transfer assembly 20, and a photographic drum assembly 22. Those skilled in the art will realize that there are other additional consumable items which can also be plug connected to a printer, in addition to the aforementioned consumable parts. Each consumable item includes a fuse 24 that is blown by fuse blow circuitry module 26 upon completion of a calibration action by control computer 28. Fuse 24 is incorporated into the structure of each of the replacement items and is connected via a single wire to a contact 30 in a multiple contact connector, which interfaces with a connector in the printer. A ground connection 32 within the replacement item enables a complete circuit to be made through fuse 24.
It is an object of this invention to provide a replaceable part/consumable with an integral memory that enables both usage and calibration data to be stored and altered.
It is another object of this invention to provide a replaceable part/consumable with a memory module that requires no modification to a preexisting physical interface between the part/consumable and apparatus in which the part/consumable is placed.